砂土中海上锚板抗拔极限状态的可靠度分析  

Reliability of offshore plate anchor design in sand for uplift limit state

作　　者：李雨婷 陈晓斌[1] 何鹏鹏 LI Yu-ting;CHEN Xiao-bin;HE Peng-peng(School of Civil Engineering,Central South University,Changsha,Hunan 410075,China;Dundee International Institute,Central South University,Changsha,Hunan 410075,China;School of Science and Engineering,University of Dundee,Dundee,UK)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学邓迪国际学院,湖南长沙410075 [3]邓迪大学科学与工程学院,英国邓迪

出　　处：《岩土力学》2023年第12期3495-3500,共6页Rock and Soil Mechanics

基　　金：中国中铁股份有限公司科技研究开发计划(No.2022-重大专项-07)。

摘　　要：为了利用深水区的大量海上风力资源,海上风电行业需要转向使用锚定系统固定在海床上的浮式风力发电机组(floating offshore wind turbines,FOWTs)。其中,锚定系统的设计对复杂海上条件下的浮式风力发电机组的稳定性和安全性至关重要。作为一种基于可靠度的简化设计方法,分项安全系数法在当前的海上基础设计中仍然非常重要,但其是否能够达到预设的目标安全水平仍有待研究。为此,考虑了多种荷载组合情况,对竖向荷载作用下砂土中的条形锚板的抗拔极限状态进行了可靠度分析。估算了采用分项安全系数法设计的条形锚板的破坏概率,并与目标安全水平进行了比较。结果表明,随着永久荷载与可变荷载比例系数的增加,分项安全系数法设计的条形锚板的可靠度指标迅速下降,并逐渐收敛到相对稳定的状态。此外,在较大的永久荷载与可变荷载比例系数范围内,分项安全系数法对海上锚板的设计都是相对保守的。从概率角度揭示了分项安全系数法的有效性,有助于进一步分析海上锚板的可靠性。The offshore wind industry needs to move towards floating offshore wind turbines(FOWTs)that are secured to the seabed with anchoring systems in order to harness the more substantial amounts of offshore wind resources available in deep waters.The design of the anchoring system for FOWTs is crucial to ensure stability and safety in challenging offshore conditions.As a simplified reliability-based design approach,the partial safety factor method remains important in current offshore foundation design practice,but its effectiveness in achieving the required target safety level still needs to be examined.To achieve this end,a reliability analysis is performed for the uplift limit state design of strip plate anchors embedded in sand subjected to vertical loads,and a wide range of load cases are considered in the analysis.The failure probabilities of strip plate anchors designed with the partial safety factor method are estimated and then compared to the target safety levels.The results show that the estimated reliability index decreases rapidly with the increasing of permanent to variable action ratio and gradually converges to a relatively steady state.In addition,the current partial safety factor method has been shown to be conservative for offshore plate anchor design over a wide range of permanent to variable action ratios.The results provide probabilistic insights into the effectiveness of the partial safety factor method and may aid in the further development of reliability analysis for offshore anchors.

关 键 词：可靠度分析 分项安全系数法 抗拔极限状态 海上锚板 排水条件 

分 类 号：TU475[建筑科学—结构工程]